The invention relates to a casing for lubricating a camshaft of an internal combustion engine for automotive vehicles, especially for a top-positioned camshaft in an internal combustion engine of V-type construction, this casing being provided with at least one lateral overflow port to maintain the oil at a constant level.
A casing for the splash lubrication of a camshaft of an internal combustion engine for automotive vehicles has been known from U.S. Pat. No. 3,033,314. This casing is formed by an oil collecting chamber cast, in case of an internal combustion engine of V-type construction, between the cylinder rows in the crankcase and extending over the entire length of the crankcase; this collecting chamber is subdivided into sections by walls receiving the bearing units carrying the camshaft. The oil flowing into the oil collecting chamber is collected therein until the individual cams of the camshaft are partially immersed in the oil. The height of the oil level is determined by overflow bores, from which the oil is returned into the oil pan.
Such splash lubrication systems for the cams of camshafts have proven themselves relatively well under practical conditions and are therefore employed nowadays to an increasing extent. However, there is the disadvantage in this conventional camshaft casing that when the vehicle is moving up or down an incline the oil level is elevated along respectively one side of the oil collecting chamber and/or along respectively one side of its individual sections so that it exceeds the level of the overflow bores and thereby such an amount of oil is discharged via the overflow bores from the oil collecting chamber that an adequate lubrication of the cams shaft is no longer ensured.
It is an object of this invention to avoid this disadvantage by an economical measure and to provide a camshaft lubrication which ensures a flawless lubrication in all positions assumed by the vehicle.
According to the invention, this object is attained by providing that the overflow port has a configuration which flares in the manner of a conical shape toward the side facing away from the camshaft and extends at least approximately in parallel to the camshaft axis. Thereby, solely due to the alteration in the configuration of the overflow bores, a camshaft lubrication has been created which is functional in all positions of the vehicle, which ensures a high operating safety of the internal combustion engine with regard to camshaft lubrication, and which moreover is maintenance-free.
In a suitable embodiment of the invention, the overflow port has a trapezoidal configuration, which widens toward the side facing toward the camshaft, and merges subsequent thereto into a cylindrical configuration.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a single embodiment in accordance with the present invention.